1. Field of the Invention
The present invention relates to coaxial connectors. In particular, the internally locking coaxial connector is a female coaxial connector with a lock washer placed inside the coupling nut that produces a constant tension against a mated male coaxial connector to prevent its loosening or separation during use, especially during periods of vibration and thermal cycling.
2. Description of the Related Art
The present invention is directed to a coaxial cable connector in which the female connector is modified to include a lock washer that applies a constant tension against a mated male connector to reduce or prevent the resulting connection from loosening during use, especially in situations of excessive vibration and thermal cycling.
Coaxial cables come in a variety of sizes and styles, including various configurations of central signal-carrying conductors and shielding. The cables are exposed to environmental factors during their use, whether used indoors or outdoors. Connectors are used to connect cables to respective terminals on electrical equipment and related housings, as well as to other cables. The cables contain a center conductor that carries an electrical signal, e.g. a radio frequency (RF) signal. Signal frequencies typically range from just under 1 MHz to the gigahertz region. A cylindrical dielectric layer surrounds the signal-carrying center conductor, and a cylindrical conductive shielding layer surrounds the dielectric. Finally, a jacket surrounds the shielding layer to complete the cable.
No matter what the frequency of the RF signal, it is important that the shielding layer, and the signal-carrying center conductor when the connector has a center pin, maintain good contact with the connector, and that the connection between a male and a female coaxial cable connector securely maintains continuity between the respective shields of the coaxial cables and between the center conductors of the respective cables in order to avoid insertion loss and to establish a consistently strong signal during use. However, during use, various factors can cause the connectors to loosen, thereby separating the connectors from each other and resulting in loss of signal.
The present invention reduces or eliminates the loss of signal by preventing threaded male and female coaxial cable connectors from separating during use. This is accomplished by incorporating a lock washer inside the female connector that produces a constant tension against a mated male connector.
U.S. Pat. No. 3,390,374, issued to Forney, Jr. on Jun. 25, 1968, teaches a coaxial connector including a locking member using an annular rib or radially inwardly directed barbs to hold a connector onto the prepared end of a cable. U.S. Pat. No. 3,778,535, issued to Forney, Jr. on Dec. 11, 1973, teaches a coaxial connector in which the outer conductor of a cable is squeezed during application of a connector.
U.S. Pat. No. 4,915,651, issued to Bout on Apr. 10, 1990, teaches a coaxial cable connector using two springs to apply axial tension to compensate for axial tolerances when the connector is applied. U.S. Pat. No. 5,195,905, issued to Pesci on Mar. 23, 1993, teaches a coaxial connector including an outer locking ring. U.S. Pat. No. 5,548,088 issued to Gray et al. on Aug. 20, 1996, teaches a coaxial connector in which a radial force is applied on a contacting member to provide on-going pressure engagement between the contacting members without the need for continuance of axial pressure to maintain electrical continuity.
U.S. Pat. No. 5,564,938, issued to Shenkal et al. on Oct. 15, 1996, teaches a coaxial cable connector having an outer sleeve member used to prevent unauthorized cable removal. U.S. Pat. No. 5,595,499, issued to Zander et al. on Jan. 21, 1997, teaches a coaxial connector having improved locking capabilities using radially movable locking arms.
U.S. Pat. No. 5,607,325, issued to Toma on Mar. 4, 1997, teaches a coaxial cable connector including a locking member using radially extending ribs that provide a frictional lock. U.S. Pat. No. 5,651,498, issued to Locati et al. on Jul. 29, 1997, teaches a coaxial cable connector including a ferrule having serrations for mechanically connecting with parts of a cable, a mandrel and a closing collar. U.S. Pat. No. 5,938,465, issued to Fox, Sr. on Aug. 17, 1999, teaches a quick connect-disconnect cable connector.
U.S. Pat. No. 6,010,349, issued to Porter, Jr. on Jan. 4, 2000, teaches a multi-piece connector having pieces that are torqued in two directions to lock the connector onto the cable.
Although various connectors are available for use on coaxial cables, there is a need for a coaxial cable connector that resists or prevents loosening between the male and female connector members during use. Such loosening might occur as a result of thermal cycling, vibration or routine use. The internally locking coaxial connector of the present invention fulfills this need by providing a lock washer member that is inserted in the female connector member with a conductive inner body, so that when the male connector member is threaded into the female member, the lock washer is compressed. The lock washer then produces a continuous tension against the male member that holds the male member at its threads firmly in place against the corresponding threads of the female member, thereby preventing its movement during use.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus an internally-locking coaxial connector solving the aforementioned problems is desired.
The present invention is directed to a threaded connector for use in a coaxial cable. In particular, the inventive connector is a female connector including a conductive flanged insert and a lock washer member placed next to the flange so that when a corresponding male connector member is threaded into the female member, the contacting face of the male connector bears against the flanged insert and presses against the lock washer member, compressing the lock washer, thereby resulting in a constant tension being applied by the lock washer against the male member that prevents its movement during vibration or thermal cycling.
Accordingly, it is a principal object of the invention tot provide a threaded coaxial cable connector having a female connector portion including a flanged insert and a lock washer positioned between the flange of the insert and an internal flange of the female member.
It is another object of the invention to provide a coaxial cable connector wherein after threaded mating of a corresponding male member into the female member, a lock washer member applies a constant tension against the male member to limit or prevent its movement during thermal cycling or vibration.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.